The frequency response of pressure transducers can be critically important for many measurements. In some applications, it is important to have very fast response times such that transient pressure phenomena may be measured. However, in other applications, it may be important to slow down or reduce transients in the applied pressures to insure the long-term survivability of the pressure transducer. In fuel and hydraulic systems there is often a steady state pressure that is important to monitor; however, in addition to this steady state pressure, there are dynamic pressure associated with pump ripple, valve opening and closing, etc. The dynamic pressures may be many times the steady state pressure and their frequencies are often such that they can excite the resonant frequency of the tubing. This resonance excitation can further amplify the dynamic pressures and cause them to permanently damage the pressure transducer, particularly if the transducer is designed to monitor the relatively low static pressure.
There are many different transducer structures designed to mitigate these dynamic pressures. Adding a pressure snubber or resonator in the front of the transducer is the most common way to control pressure amplitudes at certain frequencies. There are also transducer housing designs, such as described in U.S. Pat. No. 9,116,056 that can eliminate or reduce transients. Such transducer designs often rely on a single narrow path (with or without an in-line sintered/porous filter structure) in communication with a cavity to act as a Helmholtz resonator, with resonance characteristics designed such that high frequency pressure components are attenuated. Such designs can work quite well, but a filter having a single path and/or an in-line porous filter can become clogged over time when particulates in the measurement media accumulate. Such a clogged path/filter can cause the transducer to malfunction.